Momyer, William M. Air power in three wars, DIANE Publishing,
ISBN1-4289-9396-7. pp. 190–192. This book contains a full quotation of the two paragraphs quoted here, and cites the source as Albert Speer. Spandau, The Secret Diaries, New York: Macmillan and Company, 1976, pp. 339–340
Thompson, Wing Commander H. L. (1956). "Chapter 5: With Mine, Bomb, and Torpedo". New Zealanders with the Royal Air Force (Vol. II). The Official History of New Zealand in the Second World War 1939–1945. Wellington: Historical Publications Branch.